1. Field of the Invention
The present general inventive concept relates to an image forming apparatus and a control method thereof, and, more particularly, to an image forming apparatus capable of sensing entry and exit of paper using a current change value of a press roller and a control method thereof.
2. Description of the Related Art
A paper supply device of an image forming apparatus includes a feed sensor and register rollers. The feed sensor serves to generate signals indicating whether or not paper is picked up and the beginning of image formation. As paper is picked up and moved upward, a tip end of the paper vibrates based on a curling degree thereof. To reduce deviation at the tip end, a register sensor is used to indicate departure of the paper after the paper is aligned with the feed sensor indicating whether or not the paper is picked up. In operation, the feed sensor determines whether or not paper is picked up, enabling recognition of a paper jam, and the register rollers temporarily stop and align the paper if the tip end of the paper reaches between the register rollers. Thereafter, as the paper is moved via a clutch-on operation, the paper strikes the register sensor when passing the register sensor. On a basis of a time when the register sensor is turned on, a controller commands initiation of image formation. Image formation is stopped when the register sensor is turned off.
Conventionally, in the case where recognition of entry and exit of paper depends on the register sensor, paper vibration may cause the image forming apparatus to experience a paper jam, or image omission during printing.